If you want to go completely mono on your panel, Jan-Christoph Borchardt created 2 great mono themes for DockBarX: Mono-Dark and Mono-Light as well as a Minimal theme - which you can see in the screenshot below:

To install the themes, you'll need to get them via BZR. To make that easy for you, the below commands will install bzr, get the themes and move them to the right folder - ready to be used: